ABSTRACT
The objective of the study was to develop a simple, specific and stability-indicating HPLC method for the simultaneous determination of creatine phosphate sodium [CPS] and its related substances in pharmaceutical formulation. Separation of creatine phosphate sodium from its major process impurities and degradation products was achieved on a Hypersil BDS C18 column [250 × 4.6 mm, 5 microm] with an aqueous mobile phase containing 0.2% [w/v] tetrabutylammonium hydroxide [TAH] and 0.2% [w/v] monopotassium phosphate adjusted to pH 6.6 with orthophosphoric acid at a flow rate of 1.0 mL min-1. The analytes were detected at 210 nm. Different chromatographic parameters were carefully optimized. The relative response factors for creatine, creatinine and creatinine phosphate disodium salt relative to CPS were determined. The method has been validated with respect to solution stability, system suitability, LOD, LOQ, linearity, accuracy, precision, specificity and robustness. The validation criteria were met in all cases. The developed method was successfully applied to determine the purity of CPS in pharmaceutical formulation
Subject(s)
Chromatography, High Pressure Liquid , Drug Stability , Chemistry, PharmaceuticalABSTRACT
The amino group PEGylation of rhIFNomega with monomethoxy polyethylene glycol succinimidyl succinate (mPEG-SS, 20 000) was investigated, and the modified mixture was separated and purified by ion exchange chromatography and gel filtration chromatography. Under the optimized purification conditions, the average content ofmono PEG-rhIFNomega in the collect liquid reached 182 microg x mL(-1). The average purified yield of mono PEG-rhIFNomega exceed to 22%, and the purity of mono PEG-rhIFNomega was greater than 98% by SDS-PAGE and RP-HPLC. Relative molecular mass of mono PEG-rhIFNomega was 43 790 detected by MALDI-TOF MS. The apparent molecular mass measured by SDS-PAGE was about 60 810. The purified PEG-rhIFNomega has the characteristics of typical PEGylated protein. Activity reservation rate of mono PEG-rhIFNomega was 15.0%, while the antigenicity decreased by at least 64 folds. In addition, the acid stability, thermal stability and stability in serum and trypsin solution of mono PEG-rhIFNomega were markedly better than those of the rhIFNomega. The pharmacological properties of mono PEG-rhIFNomega were significantly improved. The prepared PEG-rhIFNomega might be developed to a novel safe and long-acting interferon.
ABSTRACT
Objective To study the process and mechanism of embryonic development and replacement of the teeth of Alligator sinensis. Methods The proccess of embryonic development and replacement of the teeth of Alligator Sinensis was studied by paraffin serial sections, the structure of the teeth of Alligator sinensis was studied by scanning electron microscopy. Results The tooth wrinkle appeared at the 20th day of incubation; the dental germ appeared at the 56th day of incubation; the crown appeared, and the dental germ came into the bottom of the alveolus dentalis at the 16th day after the young alligator was out of the eggshell. From one year to five year alligators, there was a dental germ at the bottom of the alveolas dentalis that would form new tooth after the old tooth was lost. Conclusion The tooth wrinkle might motivate embryonic development of the teeth of Alligator sinensis ; the dental germ at the bottom of the alveolus dentalis formed directly the new tooth in the process of tooth replacement. [